Getting to the bones

Very often the fossils that are seen on display in museums or in papers are beautifully clear of surrounding rock, or are carefully exposed on a slab or block of matrix. When TV shows want to cover fossil preparation we see something rapidly fall out of sandstone, or delicate cleaning of the last bits of rock from a specimen. What they don’t tend to show, and what you won’t see from a complete preparation job is how hard it may have been to get there. Here are some blocks of material from the UK that contain various bits of the early saurischian Thecodontosaurus.

What you can hopefully see if that the matrix in an ungodly conglomerate whose defining feature is just how tough the stuff is. I did some work on this many year ago and it could take hours to expose even just the end of a bone. Rock would flake off in only the smallest amounts (and you can see the endless white scorelines across the surface in the photos) so it took huge effort to take out even a few cubic centimeters of rock. We had a few tons of material in the lab.

I don’t think the work of preparators is under appreciated by palaeontologists or those who just generally like fossils. Without them we would often have fewer nice specimens to work on, and their experience and knowledge can be invaluable in the field and in research. However what might not be appreciated is just how much work can go into the job. In this case it took me something like 5 hours of work to expose the end of a small croc femur about 5 mm long. It should therefore be clear just how much work went into preparing the dozens (perhaps by now hundreds) of elements that have come from this quarry.